US police are investigating the stepfather of black shooting victim Michael Brown for inciting illegal activity during protests in Ferguson.

Video of Louis Head shows him yelling "Burn this [place] down!" before last week's riots over perceived racial injustice in the Missouri town.

He spoke as a grand jury announced no charges for a white police officer who shot and killed the unarmed teenager.

The incident sparked a nationwide dialogue about race relations.

St Louis County Police spokesman Brian Schellman told US media on Tuesday authorities want to talk to Mr Head about his comments amid a larger investigation into arson and looting during the Ferguson protests.

Twelve commercial buildings were destroyed by fire that night, after the jury's decision was announced.

Family attorney Benjamin Crump has called Mr Head's recorded comments "raw emotion".

Image copyrightReutersImage caption
A grand jury decision not to charge a police officer in a fatal shooting sparked widespread protests across the US

The officer who shot Brown in Ferguson, Darren Wilson, resigned from the force over the weekend.

The policeman said he had feared for his life, but Brown's supporters said the teenager was attempting to surrender when he was shot.

Some witnesses said the 18-year-old, who was unarmed, had his hands up.

The investigation into Mr Head comes one day after President Barack Obama requested $263m (£167m) to improve police training, pay for body cameras and restore trust in policing.

"This is not a problem just of Ferguson, Missouri. This is a national problem, Mr Obama said. "But it's a solvable problem."